Rotary agitator for providing oscillating anp cleaning action

ABSTRACT

A rotary agitator for a cleaning apparatus includes a body having an axis of rotation and a zero degree pitch plane perpendicular to the axis of rotation. The rotary agitator also includes an agitation element carried on the body. The agitation element includes a first portion provided at a positive pitch angle relative to the zero degree pitch plane and a second portion provided at a negative pitch angle relative to the zero degree pitch plane.

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/623,416 filed on 29 Oct. 2004.

TECHNICAL FIELD

The present invention relates generally to the floor care equipmentfield and, more particularly, to a rotary agitator with an agitatorelement providing oscillating nap cleaning action, a floor careappliance equipped with such a rotary agitator and to a method ofcleaning a carpet or rug.

BACKGROUND OF THE INVENTION

A vacuum cleaner is an electrically powered, mechanical applianceutilized for the dry removal of dust and loose dirt from carpets, rugs,fabrics and other surfaces. Vacuum cleaners have been widely utilizedfor years in domestic and industrial cleaning applications.

In operation, a pressure drop is utilized to force air entrained withloose dirt and dust into the nozzle of the vacuum cleaner. The dust anddirt laden air is then drawn through a bag or dirt cup which traps andretains the dirt. The air is then exhausted by electric fan through anadditional filter to remove relatively fine particles. It is this fanthat provides the air pressure drop or vacuum that provides the cleaningaction.

The present invention relates to a rotary agitator for a floor cleaningapparatus such an upright vacuum cleaner, canister vacuum cleaner,handheld vacuum cleaner, an extractor or the like. The rotary agitatoris equipped with one or more agitation elements adapted to sweep the napof an underlying rug or carpet in an oscillating, side-to-side manner.This cleaning action functions to more efficiently and effectivelyloosen and expose dirt and debris embedded down in the nap of a rug orcarpet to the suction airstream so that it may be quickly drawn into thevacuum cleaner. This results in better cleaning.

SUMMARY OF THE INVENTION

In accordance with the purposes of the present invention as describedherein, a rotary agitator is particularly adapted to provide highefficiency, deep cleaning of dirt and debris from the nap of anunderlying rug or carpet. The rotary agitator includes a body that hasan axis of rotation and a zero degree pitch plane perpendicular to thataxis of rotation. Further the rotary agitator has at least one agitationelement having a first portion provided at a positive pitch anglerelative to the zero degree pitch plane and a second portion provided ata negative pitch angle relative to the zero degree pitch plane.

The agitation element may comprise any number of different structuresincluding but not limited to a series of bristle tufts, a wiper, a brushand a beater bar. The agitation element may be substantially continuousor even comprise an oscillating ring.

Stated another way, the rotary agitator of the present inventioncomprises a body including an axis of rotation and a zero degree pitchplane perpendicular to that axis of rotation. In addition, the rotaryagitator includes at least one endless agitation element carried on thebody and straddling the zero degree pitch plane. More specifically, theendless agitation element includes (a) a first portion extending in afirst arc from the zero degree pitch plane to a first point a firstdistance in a first direction from that pitch plane and then back to thepitch plane and (b) a second portion extending in a second arc from thepitch plane to a second point a second distance in a second directionfrom the pitch plane and then back to the pitch plane. That firstdistance A may be between about 0.5 and 3.0 cm. Further, the seconddistance may be substantially equal to the first distance.

In accordance with another aspect of the present invention a method isprovided for removing dirt and debris from the nap of a rug or carpet.The method comprises providing a rotary agitator with an oscillatingagitation element that functions to push the nap in a side-to-sidemotion during rotation of the rotary agitator.

In accordance with yet another aspect of the present invention a floorcleaning apparatus is provided. That floor cleaning apparatus comprisesa housing, a suction generator carried on the housing, a dirt collectionvessel carried on the housing and the rotary agitator of the presentinvention.

In the following description there is shown and described severalpossible embodiments of the invention, simply by way of illustration ofsome of the modes best suited to carry out the invention. As it will berealized, the invention is capable of other different embodiments, andits several details are capable of modification in various, obviousaspects all without departing from the invention. Accordingly, thedrawings and descriptions will be regarded as illustrative in nature andnot as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification, illustrate several aspects of the present invention, andtogether with the description serve to explain certain principles of theinvention. In the drawings:

FIG. 1 is a perspective view of the rotary agitator of the presentinvention;

FIG. 2 a is a schematical elevational view illustrating the geometry ofthe agitation element carried on the agitator;

FIG. 2 b is a detailed perspective, schematical view illustrating thearcs formed by the agitation element;

FIGS. 3 a and 3 b are schematical side elevational views illustratinghow the rotary agitator functions to push or brush the nap of anunderlying carpet from side-to-side;

FIG. 4 illustrates a vacuum cleaner equipped with the agitator of FIG.1; and

FIGS. 5 a-5 f illustrate several additional embodiments of the rotaryagitator of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIG. 1 illustrating the rotary agitator 10 ofthe present invention. The rotary agitator 10 includes a body 12. In theillustrated embodiment the body 12 is cylindrical in shape but othershapes could be provided. The body 12 may be molded from plastic,machined or cast from metal such as aluminum or constructed from anyother appropriate material. In the illustrated embodiment the body 12carries an axle or stub shafts 14 that extend from each end. As bestillustrated in FIG. 2 the body 12 also includes an axis of rotation 16defined by the axle or stub shafts 14 and a zero degree pitch plane 18perpendicular to the axis of rotation 16.

As also illustrated in FIGS. 1, 2 a and 2 b, at least one agitationelement 20 is carried on the body 12 of the rotary agitator 10. Theagitation element 20 may assume any appropriate form including but notlimited to a wiper, a brush, a beater bar and a series of bristle tufts.Each element 20 may be molded as an integral part of or affixed to theagitator body 12. In the illustrated embodiment, each agitation element20 is substantially continuous so as to be effectively endless. Further,each agitation element 20 straddles the zero degree pitch plane 18 so asto effectively form an oscillating ring as the agitator 10 is rotated(note particularly FIG. 2 a) with respect to a fixed point on thesurface being cleaned.

More specifically, each agitation element 20 has a first portion 22provided at a positive pitch angle A₁ relative to the zero degree pitchplane 18 and a second portion 24 provided at a negative pitch angle A₂relative to the pitch plane 18.

Described another way each endless agitation element 20 includes a firstarc 26 extending from the pitch plane 18 to a first point 28 a firstdistance in a first direction from the pitch plane 18 and then back tothe pitch plane (see FIG. 2 b). Additionally, the agitation element 20includes a second arc 30 extending from the pitch plane 18 to a secondpoint 32 a second distance in a second direction from the pitch plane 18and then back to the pitch plane. The distance between the first point28 and the pitch plane 18 may be between about 0.5 and 3.0 cm. Thesecond distance between the second point 32 and pitch plane 18 may besubstantially equal to that first distance.

As the rotary agitator 10 rotates about the axis of rotation 16, theagitation elements 20 first push, brush or comb the nap of an underlyingcarpet being cleaned in a first direction toward the ends of theagitator (note action arrows D₁ in FIG. 3 a). Pushing, brushing orcombing nap in this direction occurs as the rotary agitator rotatesthrough the first 180 degrees of its rotation.

As the rotary agitator 10 rotates through its second 180 degrees ofrotation, the nap of the underlying rug or carpet being cleaned ispushed, brushed or combed in a second opposite direction toward themiddle of the agitator (note action arrows D₂ in FIG. 3 b) by theagitation elements 20.

As the rotary agitator 10 continues to rotate, the nap is brushed backand forth from side to side so as to insure that dirt and debris on twosides of the nap is not only loosened but also fully exposed to thesuction airstream of the floor cleaning device to which the rotaryagitator is attached. This differs from agitators of the prior art thatincorporate agitation elements that only brush the nap to one sidethereby laying the nap over to that one side and holding it there so asto trap dirt and debris underneath the nap. By avoiding this problem,the present invention insures more efficient and effective deep cleaningof the underlying rug or carpet.

A vacuum cleaner 50 incorporating a rotary agitator 10 of the presentinvention is illustrated in FIG. 4. The vacuum cleaner 50 includes ahousing, generally designated by reference numeral 52, including anozzle assembly 54 and a handle assembly 56. As is known in the art, thehandle assembly 56 is pivotally connected to the nozzle assembly 54 toaid the operator in manipulating the vacuum cleaner 50 back and forthacross the floor. Wheels (not shown) carried on the housing 52 allow thevacuum cleaner 50 to be moved smoothly across the floor. As illustrated,the nozzle assembly 54 is equipped with a nozzle inlet 58. The rotaryagitator 10 is mounted for rotation on the nozzle assembly 54 across thenozzle inlet 58 by means of an end cap and bearing assembly 59 providedon each end of the agitator 10 in a manner well known in the art (seeFIGS. 3 a and 3 b).

The housing 52 houses a suction generator 62 (i.e. a fan and motorassembly) and a dirt collector 64 having an internal dirt collectionchamber. In one possible embodiment, the dirt collector 64 comprises afilter bag. In another possible embodiment the dirt collector 64comprises a dirt cup. That dirt cup may be substantially cylindrical inshape and include a tangentially directed air inlet and an axiallydirected air outlet. Such a structural arrangement produces cyclonicairflow which helps separate dirt and debris from the airstream andincrease cleaning efficiency.

The handle assembly 56 also includes a control stalk 68 and an actuatorswitch 66 for turning the vacuum cleaner 50 on and off and therebydriving the rotary agitator 10 and the suction generator 62.

In operation, the rotary agitator 10 efficiently brushes dirt and debrisfrom the nap of an underlying carpet. By brushing the nap fromside-to-side, dirt and debris on both sides of the nap is exposed to thevacuum airstream so that it may be more efficiently drawn into thevacuum cleaner (note agitation elements 20 aligned with suction inlets67 in the nozzle assembly 54 as illustrated in FIG. 3 a). Thisrepresents a significant improvement over prior art agitators that tendto brush nap to one side laying that nap over dirt and debris on thatside and effectively shielding that dirt and debris from the vacuumairstream. Loosened dirt and debris is drawn into the dirt collector 64through the suction inlets 67 by means of the suction generator 62. Dirtand debris is trapped in the dirt collector 64 and the now clean air isdirected over the motor of the suction generator 62 before beingexhausted into the environment through the exhaust vent 70.

The foregoing description of a preferred embodiment of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed. Obvious modifications or variations are possible in light ofthe above teachings. For example, while the illustrated embodiment inFIG. 4 is an upright vacuum cleaner 50, the present invention alsorelates to and includes canister and handheld vacuum cleaners as well asextractors. Further, while the illustrated embodiment is a “clean air”system with a suction generator 62 downstream from the dirt collector64, the present invention also includes “dirty air” systems where thesuction generator is located upstream of the dirt collector. Further,while the illustrated vacuum cleaner 50 includes one rotary agitator 10,it could include two or more rotary agitators if desired.

It should also be appreciated that the agitator 10 may also take theform of other embodiments as illustrated in FIGS. 5 a-5 e. In FIG. 5 a,the agitator 10 includes a series of separate and parallel cleaningrings 80 for agitation elements. In FIG. 5 b, the agitation element is asingle, coiled element 82 that extends around and along the length ofthe agitator 10. All portions of the element 82 angle in the samedirection with respect to plane 18 but the amount of the included anglevaries to produce an oscillation as the agitator 10 rotates. In FIG. 5c, the agitator 10 includes agitation elements comprising a series ofseparate and alternating cleaning rings 84.

In FIG. 5 d, the agitator 10 includes two sets of separate cleaningrings 86, 88. The first set of rings 86 are on a first side of thecenterline CL of the agitator 10 and are angled in a first direction.The second set of rings 88 are on a second side of the centerline CL andare angled in a second direction. The number of rings in each set matchand the angles of inclination are equivalent so that all forces arebalanced and the nozzle is steady as the agitator 10 rotates. In FIG. 5e two separate coils 90, 92 are provided with one on each side of thecenterline CL of the agitator 10. The coils 90, 92 are mirror images ofeach other. In FIG. 5 f, an agitator 10 is illustrated incorporatingmultiple oscillating elements 94 having varying angles with respect tothe pitch plane 18 mirrored about the center line CL.

The embodiments were chosen and described to provide the bestillustration of the principles of the invention and its practicalapplication to thereby enable one of ordinary skill in the art toutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. All suchmodifications and variations are within the scope of the invention asdetermined by the appended claims when interpreted in accordance withthe breadth to which they are fairly, legally and equitably entitled.The drawings and preferred embodiments do not and are not intended tolimit the ordinary meaning of the claims and their fair and broadinterpretation in any way.

1. A rotary agitator, comprising: a body including an axis of rotationand a zero degree pitch plane perpendicular to said axis of rotation;and at least one agitation element having a first portion provided at apositive pitch angle relative to said zero degree pitch plane and asecond portion provided at a negative pitch angle relative to said zerodegree pitch plane.
 2. The rotary agitator of claim 1, wherein said atleast one agitation element is a series of bristle tufts.
 3. The rotaryagitator of claim 1, wherein said at least one agitation element is awiper.
 4. The rotary agitator of claim 1, wherein said at least oneagitation element is a brush.
 5. The rotary agitator of claim 1, whereinsaid at least one agitation element is a beater bar.
 6. The rotaryagitator of claim 1, wherein said at least one agitation element isselected from a group consisting essentially of a series of bristletufts, a wiper, a brush, a beater bar, a molded rib and combinationsthereof.
 7. The rotary agitator of claims 1, wherein said at least oneagitation element is substantially continuous.
 8. The rotary agitator ofclaims 1, wherein said at least one agitation element is an oscillatingring.
 9. A rotary agitator, comprising: a body including an axis ofrotation and a zero degree pitch plane perpendicular to said axis ofrotation; and at least one endless agitation element carried on saidbody and straddling said zero degree pitch plane.
 10. The rotaryagitator of claim 9 wherein said at least one endless agitation elementincludes (a) a first arc extending from said zero degree pitch plane toa first point a first distance in a first direction from said zerodegree pitch plane and then back to said zero degree pitch plane and (b)a second arc extending from said zero degree pitch plane to a secondpoint a second distance in a second direction from said zero degreepitch plane and then back to said zero degree pitch plane.
 11. Therotary agitator of claim 10, wherein said first distance A is betweenabout 0.5 and 3.0 cm.
 12. The rotary agitator of claim 11 wherein saidsecond distance is substantially equal to said first distance.
 13. Amethod of removing dirt and debris from nap of a rug or carpet,comprising: providing a rotary agitator with at least one oscillatingagitation element that functions to push the nap in a side-to-sidemotion during rotation of said rotary agitator.
 14. A floor cleaningapparatus, comprising: a housing; a suction generator carried on saidhousing; a dirt collection vessel carried on said housing; and a rotaryagitator carried on said housing, said rotary agitator having a bodyincluding an axis of rotation and a zero degree pitch planeperpendicular to said axis of rotation and at least one agitationelement having a first portion provided at a positive pitch anglerelative to said zero degree pitch plane and a second portion providedat a negative pitch angle relative to said zero degree pitch plane. 15.A floor cleaning apparatus, comprising: a housing; a suction generatorcarried on said housing; a dirt collection vessel carried on saidhousing; and a rotary agitator carried on said housing, said rotaryagitator having a body including an axis of rotation and a zero degreepitch plane perpendicular to said axis of rotation and at least oneendless agitation element carried on said body and straddling said zerodegree pitch plane.